Separator for shredded tobacco

ABSTRACT

A separator for shredded tobacco has a column provided at its bottom with a perforated plate inclined towards a discharge duct. An entry duct for the shredded tobacco and a feed pipe for air propels the shredded tobacco upwards. The upper mouth of the column faces a mesh conveyor movable substantially transversely to the vertical axis of the column. The conveyor forms an element by which the upward rise of the shredded tobacco is halted and is conveyed towards a member for removing and conveying the tobacco.

This invention relates to a separator for shredded tobacco.

The processing of shredded tobacco comprises a separation stage in whichthe shredded tobacco is treated both to separate it from the air and toseparate foreign bodies from it such as stones, tobacco agglomerationsetc.

This stage is currently carried out using a separator consisting of acasing provided at its bottom with a rotary valve for discharging thetobacco and at its centre with a rotating mesh cylinder or other systemfor withdrawing the air to be fed to the filter.

This system results in tobacco degradation because of the rubbing of thetobacco against the separator wall and the fact that the product iswithdrawn via the rotary valve.

The object of the invention is to eliminate these drawbacks by providinga device which enables the separation to be effected in a simple,comfortable and reliable manner, without the product undergoing“manipulation”.

This and further objects which will be apparent from the ensuingdescription are attained according to the invention by a shreddedtobacco separator as described in claim 1.

The invention is described in detail hereinafter with reference to theaccompanying drawing showing a schematic vertical section through aseparator according to the invention.

As can be seen from the drawing the separator of the invention comprisessubstantially a vertical column 2 of rectangular cross-section providedwith a connector for an entry duct 4 for the shredded tobacco and aperforated plate 6 inclined towards a duct 8 for discharging waste suchas stones, tobacco agglomerations, etc.

The column is connected at its bottom to a pipe 10 for feedingcompressed air originating from a centrifugal blower 12.

At the upper end of the column there is provided a dome 14 housing amesh conveyor 18 extending about drive and deviation rollers 20, ahorizontal portion 22 of the conveyor 18 being positioned substantiallyto close the mouth of the column 2.

An air withdrawal hood 16 is present above the horizontal portion 22 ofthe conveyor 18.

The dome 14 presents an inclined lower part 24, the upper side of whichcan be adjusted so that it lies substantially in contact with theconveyor, its lower side being substantially in contact with a dischargebelt 26.

A compressed air diffuser pipe 30 is provided facing that portion of theconveyor 18 downstream of the portion 22 which closes the mouth.

The separator of the invention operates in the following manner:

-   -   the shredded tobacco fed by the conveyor belt 34 is transferred        through the duct 4 to the interior of the column 2, where the        suitably regulated compressed air flow feeds the tobacco        particles towards the conveyor 18 while allowing the foreign        bodies such as stones and tobacco agglomerations to deposit by        gravity onto the perforated plate 6 and then descend towards the        discharge duct 8.

At the same time those particles which reach the conveyor 18 depositthereon and remain retained there along a short portion of thehorizontal path as they are subjected to suction. As soon as theparticles leave the region of influence of the suction they fall ontothe inclined surface 22 with the help of the compressed air blowing fromthe diffuser, to be then transferred to the discharge belt 26.

From the aforegoing it is apparent that the separator of the inventionenables the said stage to be effected easily and comfortably, withoutthe product undergoing “manipulation”.

1. A separator for shredded tobacco comprising a column provided at itsbottom with a perforated plate inclined towards a discharge duct, andfurther provided with an entry duct for the shredded tobacco and a feedpipe for air which propels the shredded tobacco upwards, characterizedin that the upper mouth of the column faces a mesh conveyor movablesubstantially transversely to the vertical axis of the column, saidconveyor forming an element by which the upward rise of the shreddedtobacco is halted and is conveyed towards a member for removing andconveying the tobacco.
 2. A separator as claimed in claim 1, furthercomprising a suction system situated in a position overlying theconveyor belt.
 3. A separator as claimed in claim 1, further comprisinga compressed air diffuser pipe.